During a Total Knee Arthroplasty (TKA), a surgeon needs to balance the collateral knee joint ligaments in order to ensure a stable artificial joint. Conventionally, the balance assessment is based on the surgeon's perception and experience by manually manipulating the knee joint. Assessing the ligament forces and moments acting in the knee “by hand” is subjective, and can lead to relatively large errors and repeatability problems.
In European document EP 1 304 093 by GOUGEON, a probe is used which allows the measurement of the compressive forces between each condyle of the femur and the tibial plateau. This probe comprises two load sensors, one for each condyle, and is attached to a plate-like support. A disadvantage of this probe is that it is not possible to determine the point of application of the compressive force. The moments which are important for ligament balancing remain unknown.